Sagittal alignment of spine and pelvis regulated by pelvic incidence: standard values and prediction of lordosis

Pelvis and spinal curves were studied with an angular parameter typical of pelvis morphology: pelvic incidence. A significant chain of correlations between positional pelvic and spinal parameters and incidence is known. This study investigated standards of incidence and a predictive equation of lordosis from selective pelvic and spinal individual parameters. One hundred and forty nine (78 men and 71 women) healthy adults, aged 19–50 years, with no spinal disorders, were included and had a full-spine lateral X-ray in a standardised upright position. Computerised technology was used for the measurement of angular parameters. Mean-deviation section of each parameter and Pearson correlation test were calculated. A multivariate selection algorithm was running with the lordosis (predicted variable) and the other spinal and pelvic parameters (predictor variables), to determine the best sets of predictors to include in the model. A low incidence (<44°) decreased sacral-slope and the lordosis is flattened. A high incidence (>62°) increased sacral-slope and the lordosis is more pronounced. Lordosis predictive equation is based on incidence, kyphosis, sacral-slope and ±T9 tilt. The confidence limits and the residuals (the difference between measured and predicted lordosis) assessed the predicted lordosis accuracy of the model: respectively, ±1.65 and 2.41° with the 4-item model; ±1.73 and 3.62° with the 3-item model. The ability of the functional spine-pelvis unit to search for a sagittal balance depended both on the incidence and on the variation section of the other positional parameters. Incidence gave an adaptation potential at two levels of positional compensation: overlying state (kyphosis, T9 tilt), underlying state (sacral slope, pelvic tilt). The biomechanical and clinical conditions of the standing posture (as in scoliosis, low back pain, spondylisthesis, spine surgery, obesity and postural impairments) can be studied by comparing the measured lordosis with the predicted lordosis.     

Responses of baboon cerebral and extracerebral arteries to prostacyclin and prostaglandin endoperoxide in vitro and in vivo.

The responses of baboon cerebral and extracerebral arteries to prostaglandin endoperoxide (PGH2) and prostacyclin (PGI2) were investigated on isolated arteries and in vivo by serial angiography. Both PGH2 and PGI2 could produce dose-dependent contraction or relaxation of isolated arteries. PGH2 induced relaxation was indicative of prostacyclin synthetase activity, the enzyme which converts PGH2 to PGI2. In isolated arteries tested one to four hours post mortem only the vertebral artery showed prostacyclin synthetase activity. Thus PGH2 induced contraction of cerebral arteries may be indicative of a physiological function. Vasomotor tone may in part be the result of a balance between PGH2 constriction and PGI2 dilatation. In vivo PGI2 infusion caused pronounced and prolonged dilatation of cerebral arteries, which lasted longer than the cardiovascular changes. As PGI2 is the most potent cerebral vasodilator drug tested, it may be of clinical use in the treatment of cerebral vasospasm.     

Transactional sex is the driving force in the dynamics of HIV in Accra, Ghana

OBJECTIVE: To delineate the population attributable fraction (PAF) of transactional sex in prevalent cases of HIV infection in the male adult population of Accra, Ghana. DESIGN AND METHODS: Cross-sectional study of clients who visited a sex worker (SW), of boyfriends of SW and of male personnel in prostitution venues. A questionnaire was administered and urine obtained for detection of anti-HIV antibodies. The PAF of prevalent HIV acquired from SW was calculated using a combination of data from this survey of clients, from on-going SW surveys, the national HIV surveillance system and the national census. RESULTS: HIV prevalence was 4.9% (8/162) among clients of mobile SW, 15.8% (53/335) among clients of home-based SW, 17.5% (10/57) among personnel and 32.1% (9/28) among boyfriends. A condom was used in 90% of intercourses, according to clients. Non-use of a condom was clustered in selected locations and independently associated with older age of client, frequency of intercourse with SW in the last year and current urethritis. Among the male population of Accra aged 15-59 years, 84% of prevalent cases of HIV were attributable to transactional sex. A sensitivity analysis showed that under various assumptions PAF varied between 47% and 100%. CONCLUSIONS: In Accra, approximately four-fifths of prevalent cases of HIV in adult males were acquired from SW. Comprehensive interventions providing education, condoms and treatment for sexually transmitted diseases for SW and their clients should be approached as other public health priorities and provided in all cities, large and small, of West Africa.     

The Glycine Transporter-1 Inhibitor SSR103800 Displays a Selective and Specific Antipsychotic-like Profile in Normal and Transgenic Mice

Schizophrenia has been initially associated with dysfunction in dopamine neurotransmission. However, the observation that antagonists of the glutamate N-methyl--aspartate (NMDA) receptor produce schizophrenic-like symptoms in humans has led to the idea of a dysfunctioning of the glutamatergic system via its NMDA receptor. As a result, there is a growing interest in the development of pharmacological agents with potential antipsychotic properties that enhance the activity of the glutamatergic system via a modulation of the NMDA receptor. Among them are glycine transporter-1 (GlyT1) inhibitors such as SSR103800, which indirectly enhance NMDA receptor function by increasing the glycine (a co-agonist for the NMDA receptor) levels in the synapse. This study aimed at investigating the potential antipsychotic-like properties of SSR103800, with a particular focus on models of hyperactivity, involving either drug challenge (ie, amphetamine and MK-801) or transgenic mice (ie, NMDA Nr1^neo−/− and DAT^−/−). Results showed that SSR103800 (10–30 mg/kg p.o.) blocked hyperactivity induced by the non-competitive NMDA receptor antagonist, MK-801 and partially reversed spontaneous hyperactivity of NMDA Nr1^neo−/− mice. In contrast, SSR103800 failed to affect hyperactivity induced by amphetamine or naturally observed in dopamine transporter (DAT^−/−) knockout mice (10–30 mg/kg p.o.). Importantly, both classical (haloperidol) and atypical (olanzapine, clozapine and aripiprazole) antipsychotics were effective in all these models of hyperactivity. However, unlike these latter, SSR103800 did not produce catalepsy (retention on the bar test) up to 30 mg/kg p.o. Together these findings show that the GlyT1 inhibitor, SSR103800, produces antipsychotic-like effects, which differ from those observed with compounds primarily targeting the dopaminergic system, and has a reduced side-effect potential as compared with these latter drugs.